Epigenetics Flashcards
what are genes?
Genes are made of DNA providing the blueprint for the structure and function of the human body, including behavior.
what are epigenetics?
Modern biologists do not simply argue that a gene “causes” a behavior; instead, they recognize what is known as the gene-environment interaction. This is part of a field of study known as epigenetics. Epigenetics argues that in order for a behavior to occur, genes must be “expressed.” This refers to the biological pattern of manifesting the genotype as phenotype.
what is the methylation process ?
the process when chemicals are added to the DNA molecules and repress the gene expression/transcription
what is the diathesis-stress model?
an individual’s reaction to stressful life events depends on their genetic makeup.
what are two strengths of the epigenetics theory?
allows us to find genetic variations using large sample sizes and they also recognize the interaction of environmental and biological factors.
investigates the influence of one gene specifically, so that avoids the problem often encountered in twin and family studies.
what are two limitations of the epigenetics theory?
mostly correlational and cannot establish a cause-and-effect relationship
reductionist approach to behavior. Many of the studies have problems with construct validity
what is one study done in epigenetics
Caspi et al (2003)
what are 5-HTT genes?
the serotonin transporter that is involved in the reuptake of serotonin in the brain synapses
which of the 3 conditions in Caspi was the mutation?
the two short alleles
what were the findings of Caspi?
people that had inherited one or more short version of the allele demonstrated more symptoms of depression and suicidal ideation in response to to stressful life events. the effect was stronger for those with 3 or more stressful life events. having the gene was not enough to lead to depression but it was rather the interaction of the gene with the environment
what was a follow up study to Caspi?
Wilhelm et al (2006), They found that 80 percent of those with two short 5-HTT genes became depressed after three or more negative life events in a yea
what are 4 limitations of Capsi?
correlational-no cause and effect
assumption that serotonin causes depression
self reported data
low reliability- cant be replicated
some participants who lacked the gene still became depressed
what is a strength of Caspi?
holistic- acknowledges the interaction between biology and environment as a cause to depression
